I downloaded the Ameba RTL8710AF SDK ver v3.5a GCC ver 1.0.0- without NDA from the Pine64 website and followed the UM0096 app note to set up the build environment. I use Cygwin64 terminal and SEGGER J-Link GDB server to talk to the PADI.

The first thing I tried to do was flash the example source "gpio_light_weight." All it does is make PC_4 an input that is pulled high internally. When it gets pulled low, PC_5 is supposed to go high. I open the J-Link GDB server and the Cygwin64 terminal at the same time. In the Cygwin64 terminal I type "make setup GDB_SERVER=jlink". Then I type "make flash" and they Cygwin64 terminal gives quite a few messages while the J-Link window downloads the program. After about a minute the download is complete and the last message in the J-Link window is "Starting target CPU"

Probing Pins GC_4 and GC_5 shows that GC_4 is pulled high and GC_5 is low. But when I ground GC_4 nothing happens on GC_5. Can you please help me understand what I am missing? Thanks!